1. Field of the Invention
The present invention relates to a stringed instrument. More particularly, it relates to a stringed instrument capable of generating a sound with higher harmonic components or a reverberant sound by an electrical signal.
2. Description of the Related Art
As a musical instrument having a bridge called “jawari” and sympathetic strings for adding higher harmonic components, there have been known a sitar that is an Indian classical musical instrument and viol family instruments with a device disclosed in U.S. Pat. No. 5,883,318. The sitar or an instrument with the device disclosed in U.S. Pat. No. 5,883,318 has main strings to be directly played and sympathetic strings mainly for producing resonance, wherein one end of the sympathetic string is supported by the jawari bridge.
The jawari bridge is characterized in that its contact surface with the sympathetic strings is a slightly curved convex surface, wherein when the strings vibrate, the strings are brought into contact with the convex surface not only at a first support point where the string vibration terminates but also at a point located on a vibration side of the first support point, thereby generating a string vibration sound with higher harmonic components. Such a structure is disclosed not only in U.S. Pat. No. 5,883,318 but also in U.S. Pat. No. 3,422,715 and Japanese Unexamined Patent Application Publication No. 2001-272972.
If the sympathetic strings are not supported by the jawari bridge, they will only produce an echo of the sound played with the main strings, but the sympathetic strings supported by the jawari bridge produce a resonant sound with higher harmonic components a little later than the sound played with the main strings.
For example, Japanese Unexamined Patent Application Publication No. 2001-272972 states that an upper surface of a bridge (saddle) for supporting strings is gently curved along the strings and brought into contact with the vibrating strings at two or more positions: a first contact position (first support point) where the vibration terminates and one or more second contact positions located on a vibration side of the first contact position, thereby generating harmonic overtones amply including higher components.
Moreover, a tambura that is also an Indian classical musical instrument is known as an instrument for producing a sustained sound with higher harmonic components. Typically, the tambura has four or five strings and a jawari bridge. A player plucks these strings one by one in an almost steady rhythm, creating a sustained sound in which higher harmonic components are intricately intertwined together.
In the conventional sitar or viol family instruments provided with the device disclosed in U.S. Pat. No. 5,883,318, however, the resonant sound with higher harmonic components can be generated only by playing the main strings of the instrument. The resonant sound with higher harmonic components cannot be adequately generated by a sound coming from the outside of the instrument.
That is, although the stringed instruments can produce a sound with higher harmonic components in response to the sound from the main strings, this effect cannot be obtained without the playing skills. Therefore, there are only a small number of players who can bring about and enjoy the effect. People who do not have the skills of playing these stringed instruments cannot generate and enjoy a resonant sound with higher harmonic components. In addition, when the sound from the main strings is small, it is impossible to adequately generate a resonant sound with higher harmonic components.
Moreover, since many strings are exposed to the outside of the instrument, touching a pointed end of the string may cause injury or when the string is broken, the string may spring to cause injury. Furthermore, since many strings are exposed to the outside of the instrument, it is difficult to maintain the body of the instrument.
On the other hand, the tambura needs a player who plucks the strings one by one in an almost steady rhythm. If a sound unique to the tambura, i.e., a sustained sound in which higher harmonic components are intricately intertwined together can be created without such a player, it would be welcomed.
Meanwhile, Japanese Unexamined Patent Application Publication No. H04-060594 discloses a stringed instrument comprising a string, an electromagnetic exciter and a bridge, wherein the electromagnetic exciter is driven by a command signal from a controller to vibrate the string.
In the stringed instrument of Japanese Unexamined Patent Application Publication No. H04-060594, after a key is pressed by a finger and the string is struck and vibrated by a hammer which moves in response to the key press, the vibration state of the string is controlled by an induced magnetic field from the electromagnetic exciter to vary the timbre of the string or the like. Japanese Unexamined Patent Application Publication No. H04-060594 also discloses that the excitation frequency of the electromagnetic exciter can be controlled by a command from the controller; the vibration state of the string can be varied by applying the induced magnetic field from the electromagnetic exciter to the vibrating string; the electromagnetic exciter can be moved to and set at a position corresponding to a loop of a high-frequency string vibration which generates a specific harmonic component as the string is in a constant vibration state, and the induced magnetic field can be applied thereto so as to emphasize or weaken the harmonic component; and the induced magnetic field may have an induction frequency in phase with the string vibration to emphasize the string vibration, while the induced magnetic field may be opposite in phase to the string vibration to weaken the string vibration.
However, the stringed instrument of Japanese Unexamined Patent Application Publication No. H04-060594 is basically such that after a key is pressed by a finger and the string is struck and vibrated by a hammer which moves in response to the key press, the vibration state of the string is controlled by an induced magnetic field from the electromagnetic exciter to vary the timbre of the string or the like. Therefore, since the skills to play the stringed instrument are required also in the case of Japanese Unexamined Patent Application Publication No. H04-060594, the people who do not have the playing skills cannot enjoy the sound effect disclosed in Japanese Unexamined Patent Application Publication No. H04-060594. In this respect, the technology disclosed in Japanese Unexamined Patent Application Publication No. H04-060594 is not different from the technologies disclosed in U.S. Pat. No. 5,883,318, U.S. Pat. No. 3,422,715 and Japanese Unexamined Patent Application Publication No. 2001-272972.